1. Field of the Invention
The present invention relates generally to telecommunications systems and methods for sending and receiving short messages by a mobile station, and specifically to accessing the Internet in an internet-protocol based cellular network by sending and receiving short messages.
2. Background of the Present Invention
With the increasing use of the Internet Protocol (IP) for delivering voice traffic across systems, some cellular networks have begun to implement IP internally. The IP packetizes voice and data for transmission within and between systems, and provides the benefit of shared bandwidth. Thus, instead of reserving a specific circuit for each call, as in conventional circuit-switched cellular networks, the voice and data for all calls in an IP-based cellular network can be transmitted together through the network.
Many mobile subscribers are beginning to access the Internet remotely using their Mobile Stations (MSs). However, because the air interface used for transmitting voice and data to and from MSs still relies upon circuit-switched technology, the mobile subscribers must attach a computer to their MS or purchase an MS with a built-in computer in order to access the Internet. The reason that IP cannot be used on the air interface is that a separate channel (or frequency) must be used for each MS. Therefore, all voice and data sent to and from the MS in an IP-based cellular network must be converted between packet-switched, which is used by the network, and circuit-switched, which is used by the MS.
For example, in order for a mobile subscriber within an IP-based cellular network to access the Internet, the mobile subscriber must first establish a call connection with an Internet Service Provider (ISP) within the circuit-switched network, which provides a connection to the Internet. This is accomplished by the MS transmitting a call setup message, including the B-number for the ISP to a Gatekeeper within the IP-based cellular network. Thereafter, the Gatekeeper establishes the connection between the mobile subscriber and the ISP via a Gateway to the circuit-switched network, using this B-number. Once the connection to the ISP has been established, the ISP provides an IP address to the mobile subscriber, which allows the mobile subscriber to browse the web and send and receive electronic messages.
To access a particular web site on a server on the Internet, the mobile subscriber must enter an IP address and port number for that web site on their computer and transmit this IP address and port number to the ISP via the IP-based cellular network and the Gateway. All data is passed between the web site and the computer associated with the mobile subscriber via the ISP, Gateway, IP-based cellular network and the MS attached to the computer.
This connection process is cumbersome, since there is a need to connect a laptop computer or purchase an MS with a computer built-in. In addition, the mobile subscriber must register with an ISP to access the Internet, which is costly for the mobile subscriber. Currently, there is not a way for the MS itself to access a web site on the Internet directly through the IP-based cellular network without the need for an attached or built-in computer or an ISP.
The present invention is directed to telecommunications systems and methods for allowing a Mobile Station (MS) within an IP-based cellular network to directly access a web site on the Internet by using a modified Simple Mail Transfer Protocol (SMTP). Each web site that the MS has the ability to access contains a new Application Program (AP) for receiving a request for information from the MS and providing the requested information back to the MS. Such information can include, for example, real-time stock quotes, sports scores, air/train schedules, mobile banking and even E-commerce capabilities. To retrieve the information from the web site, the MS within the IP-based cellular network originates a short message towards the AP associated with the web site using a pre-assigned E.164 number for the AP. When the short message reaches a Mobile Switching Center (MSC) within the IP-based cellular network, a new Application Manager (AM) within the MSC intercepts the short message and translates the E.164 number into an IP-address and port number for the AP. In addition, the AM extracts the short message data (information request) from the short message, packs the short message data in an SMTP envelope and transmits the short message data to the AP using a modified SMTP protocol. Once the AP receives the short message data within the SMTP envelope, the AP extracts the short message data from the SMTP envelope, retrieves the requested information and delivers the information back to the AM in the MSC. To send the information to the MS, the AM within the MSC converts the information into another short message, pages the MS and delivers the short message containing the requested information to the MS.